CustomDialplan

exten => 5656,1,Answer
exten => 5656,n,Read(CardNumber,custom/sixteendigits,16,3,25)
exten => 5656,t,Playback(custom/error)
exten => 5656,n,Read(PinNumber,custom/please-enter-your-pin,4,3,25)
exten => 5656,t,Playback(custom/error)
exten => 5656,n,Set(BAL=${CURL(https://api.com)}) ;card #
exten => 5656,n,Set(PIN=${CURL(https://api.com)}) ;pin #
exten => 5656,n,Set(PINTRIM=${PIN:23:-2})
exten => 5656,n,NoOp(${PINTRIM})
exten => 5656,n,GotoIf($["${PINTRIM}" = "PIN OK"]?goodpin:badpin)
exten => 5656,n(goodpin),Playback(custom/your-current-balance)
exten => 5656,n,SayNumber(${BAL:60})
exten => 5656,n,Playback(custom/ty-for-calling-goodbye)
exten => 5656,n,Hangup()
exten => 5656,n(badpin),Playback(custom/invalid-pin-number)
exten => 5656,n,Hangup()